The present invention relates to stick-type cosmetic compositions. More particularly, it relates to improved antiperspirant sticks.
The chemical and cosmetic literature is replete with formulations of stick-form cosmetics for various uses, such as antiperspirants, deodorants, and lipsticks. The specific stick formulation may vary depending upon such factors as the intended use, the "active" ingredient to be incorporated, and the part of the body to which the product is to be applied.
There are three main types of such cosmetic stick formulations: compressed powder sticks, gel sticks, and wax sticks. While each of these formulation types may have advantages in certain use situations, each also has disadvantages. For example, compressed powder sticks are often brittle and hard, and leave a cosmetically-unacceptable dust upon application. Gels may be unstable due to evaporation of alcohol or (in antiperspirant sticks) due to interaction of astringent metal salts with the soaps present. Wax-based formulations can also yield cosmetically-unacceptable products due to such factors such as hardness, greasiness, and stickiness.
The use of powders and particulates has been disclosed in the literature in order to modify the cosmetic and formulation characteristics of stick-type products. For example, polyethylene in a powder base has been disclosed for use in stick-form powder cosmetics in Japanese Patent specification No. 57-109,706, published July 8, 1982. Similarly, U.S. Pat. No. 4,379,136, Mochida, issued Apr. 5, 1983, discloses polyethylene as a binding aid in compressed powder cosmetic sticks. Inert powders, such as polystyrene, have also been used in gel stick formulations, as disclosed in U.S. Pat. No. 3,255,082, Barton, issued June 7, 1966. Powder materials are disclosed in a matrix of insoluble alcohols and volatile silicone oils, so as to form wax-based cosmetic sticks, in U.S. Pat. No. 4,126,679, Davy, et al., issued Nov. 21, 1978.
It has now been discovered that gel or wax-based stick cosmetic compositions, containing certain chemically inert particulates of a defined size and of low density, have superior application and in-use characterics when compared to similar cosmetic sticks not having such particles. In particular, wax cosmetic sticks of this invention incorporating astringent metal salts have improved application characteristics, such as "glide", as well as improved in-use characteristics, such as tackiness and appearance.